OBJECTIVES: 1. Continue testing and improving the previously proposed method of vestibular examination of infants and children. 2. Study the development of orienting mechanisms in space and cognitive functions in infants and children from the neonatal period 'till age 6 (preschool child). 3. Detect abnormalities in space orientation and cognitive functions in babies at high risk through a longitudinal follow-up study of the development of these functions. 4. Teach parents methods to improve the babies' balance, awareness of environment, their motor and cognitive skills. 5. Study of vestibular pathology in children presented to clinic with delayed acquisition of postural control, dysequilibrium or vertigo. 6. Treat with medication, physical therapy or surgery when indicated. METHODS: 1. Comprehensive neurological examination adapted to patient's age. 2. ENT exam to rule out possible abnormalities connected directly or indirectly with vestibular or cochlear dysfunction. 3. Hearing test adapted to patient's age. 4. Electronystagmography. 5. Denver Developmental Screening Test. 6. Psychometrics at age 3 and 5 years.